Order by disorder and phase transitions in a highly frustrated spin model on the triangular lattice

Frustration has proven to give rise to an extremely rich phenomenology in both quantum and classical systems. The leading behavior of the system can often be described by an effective model in which only the lowest-energy degrees of freedom are considered. In this paper, we study a system correspond...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Honecker, Andreas, Cabra, Daniel Carlos, Everts, H.-U., Pujol, Pierre, Stauffer, Franck
Formato:	Articulo
Lenguaje:	Inglés
Publicado:	2011
Materias:	Física Physics Phase transition Antiferromagnetism Critical exponent Coupling constant Condensed matter physics Spin model Frustration Classical limit Quantum mechanics Hexagonal lattice
Acceso en línea:	http://sedici.unlp.edu.ar/handle/10915/126457
Aporte de:	SEDICI (UNLP) de Universidad Nacional de La Plata

id	I19-R120-10915-126457
record_format	dspace
institution	Universidad Nacional de La Plata
institution_str	I-19
repository_str	R-120
collection	SEDICI (UNLP)
language	Inglés
topic	Física Physics Phase transition Antiferromagnetism Critical exponent Coupling constant Condensed matter physics Spin model Frustration Classical limit Quantum mechanics Hexagonal lattice
spellingShingle	Física Physics Phase transition Antiferromagnetism Critical exponent Coupling constant Condensed matter physics Spin model Frustration Classical limit Quantum mechanics Hexagonal lattice Honecker, Andreas Cabra, Daniel Carlos Everts, H.-U. Pujol, Pierre Stauffer, Franck Order by disorder and phase transitions in a highly frustrated spin model on the triangular lattice
topic_facet	Física Physics Phase transition Antiferromagnetism Critical exponent Coupling constant Condensed matter physics Spin model Frustration Classical limit Quantum mechanics Hexagonal lattice
description	Frustration has proven to give rise to an extremely rich phenomenology in both quantum and classical systems. The leading behavior of the system can often be described by an effective model in which only the lowest-energy degrees of freedom are considered. In this paper, we study a system corresponding to the strong trimerization limit of the spin-1/2 kagome antiferromagnet in a magnetic field. It has been suggested that this system can be realized experimentally by a gas of spinless fermions in an optical kagome lattice at 2/3 filling. We investigate the low-energy behavior of both the spin-1/2 quantum version and the classical limit of this system by applying various techniques. We study in parallel both signs of the coupling constant J since the two cases display qualitative differences. One of the main peculiarities of the J > 0 case is that, at the classical level, there is an exponentially large manifold of lowest-energy configurations. This renders the thermodynamics of the system quite exotic and interesting in this case. For both cases, J > 0 and J < 0, a finite-temperature phase transition with a breaking of the discrete dihedral symmetry group D6 of the model is present. For J < 0, we find a transition temperature T < c /\|J \| = 1.566 ± 0.005, i.e., of order unity, as expected. We then analyze the nature of the transition in this case. While we find no evidence for a discontinuous transition, the interpretation as a continuous phase transition yields very unusual critical exponents violating the hyperscaling relation. By contrast, in the case J > 0, the transition occurs at an extremely low temperature, T > c ≈ 0.0125 J . Presumably this low transition temperature is connected with the fact that the low-temperature ordered state of the system is established by an order-by-disorder mechanism in this case.
format	Articulo Articulo
author	Honecker, Andreas Cabra, Daniel Carlos Everts, H.-U. Pujol, Pierre Stauffer, Franck
author_facet	Honecker, Andreas Cabra, Daniel Carlos Everts, H.-U. Pujol, Pierre Stauffer, Franck
author_sort	Honecker, Andreas
title	Order by disorder and phase transitions in a highly frustrated spin model on the triangular lattice
title_short	Order by disorder and phase transitions in a highly frustrated spin model on the triangular lattice
title_full	Order by disorder and phase transitions in a highly frustrated spin model on the triangular lattice
title_fullStr	Order by disorder and phase transitions in a highly frustrated spin model on the triangular lattice
title_full_unstemmed	Order by disorder and phase transitions in a highly frustrated spin model on the triangular lattice
title_sort	order by disorder and phase transitions in a highly frustrated spin model on the triangular lattice
publishDate	2011
url	http://sedici.unlp.edu.ar/handle/10915/126457
work_keys_str_mv	AT honeckerandreas orderbydisorderandphasetransitionsinahighlyfrustratedspinmodelonthetriangularlattice AT cabradanielcarlos orderbydisorderandphasetransitionsinahighlyfrustratedspinmodelonthetriangularlattice AT evertshu orderbydisorderandphasetransitionsinahighlyfrustratedspinmodelonthetriangularlattice AT pujolpierre orderbydisorderandphasetransitionsinahighlyfrustratedspinmodelonthetriangularlattice AT staufferfranck orderbydisorderandphasetransitionsinahighlyfrustratedspinmodelonthetriangularlattice
bdutipo_str	Repositorios
_version_	1764820450737651712

Order by disorder and phase transitions in a highly frustrated spin model on the triangular lattice

Ejemplares similares